/Engine/Plugins/Animation/DeformerGraph/Source/OptimusCore/Public/OptimusNodeGraph.h
Returns true if the node in question is a function reference node that can be expanded into a group of nodes using ExpandFunctionToNodes.
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category=OptimusNodeGraph) bool IsFunctionReference ( [UOptimusNode](API\Plugins\OptimusCore\UOptimusNode) * InNode ) const